Rotary changeable cutter reamer



Dec. 17, 1929.

7 8L. CAMPBELL ROTARY CHANGEABLE CUTTER REAMER Filed Aug. 8, 192? 2 Sheets-Sheet 1 Patented Dec. 17, 1929 M? err STEWART I. CAMPBELL, OF. BERKELEY, CALIFORNIA, ASSIGNOB TO JOHN GRANT, '0!

LOS ANGELES, CALIFORNIA ROTARY CHANGEABLE CUTTER BEAMER Application filed August 8, 1928.

V cutter reamer. The present invention therefore relates to an improved type of renewable or changeable cutter reamer, having an improved mode of operation and improved construction. The structure and general mode of operation of the tool about to be explained are similar to the structure and mode of operation ofan expansive reamer on which I, together With JZt-IHQS J. Santiago, filed application for United States Letters Patent on February 11, 1928, Serial Number 253,541.

In said application a reamer is described which embodies generally a slotted body with cutters movable in and out through the body slots and an interior mandrel which is rotatably movable within the body, the cutters and the mandrel being also movable relatively longitudinally. The mandrel is provided with longitudinal slots and with downwardly facing shoulders or abutments intermediate the slots; so that by turning the mandrel to a certain rotative position relative to the cutters the cutters are held down and in'contracted position-by the mandrel shoulders,- whereas when the mandrel is moved to another certain relative rotative position the cutters may move up relative to the mandrel and, in moving up, be forced outwardly to their expanded position.

The present undcrreamer embodies the general features embodied in said prior application but embodies in addition the adaptation of that structure and mode of operation to changing or renewing the cutters, but utilizing one or more cutters or sets of cutters and utilizing a mandrel of such formation that with the mandrel in one relative rotating position one cutter or set of cutters is moved outward'to expanded position when the cut ers move upwardly; while in another Serial No. 298,145.

relative rotative position of the mandrel another cutter or set of cutters is movedofltwardly to expanded position upon upward motion of the cutters.

The general nature of the invention, its

typical embodiment, structure and its mode= o E operation will be best understood from-the following detailed description ofa-preferred and specific embodiment; reference for that purpose being had to the accompanying drawings in which:

Figure 1 is a vertical central section o fthe reamer showing one pair of cutters in the expanded position;

Fig. 2 is a similar view showing the cutters contracted Fig. 3 is an enlarged cross-section on -line 33 of Fig. 1; g

Fig. 4c is a similar cross-section on'li'ne 4: of Fig. 2;

Fig. 5 is a crosssection similar to that of Fig. 3 but showing the'other set of 'cutters expanded; V

Fig. 6 is a side elevationof the mandrel in the same aspectas shown in Fig. 2;

Fig. i is an enlarged cross-section on line- 77 of Fig. 6; v

Figs. 8 and'9 are longitudinal sections of the mandrel taken on lines 88and 9'9 of Fig. '4

Fig. 10 is a fragmentary side elevation sim= ilar to Fig. 6 of a modified form of mandrel.

It will be understoodthat' the accompanying drawings and followingdescription are intended only to describe one of the various specific embodiments which the invention may take and that therefore't-he following description is not to be construed as limitative of the invention, the structure and action of the present preferred form being'described to some extent of detail to give a clear and full understanding of one form of the invention. For instance, the operations hereinafter described include both relative rotation and relative longitudinal movement between the mandrel and the cutter or setsof cutters and such relative movements may beeffected by actual movement of either element, although I show here an actual'rotation of the mandrel and an actual upward movement of pairs of cutters, one pair being thrown into expanded position when the other pair is retracted. In all such matters variations of the invention are not only possible but will occur to those skilled in the art; and also any other matters, such as use or the specific arrange ment of the spring actuation of the cutters, the form and. design of the body, etc.

Thus in the accompanying drawings I illustrate a tubular body 10 which is provided with four Vertically extending cutter-receiving slots 11 through its cylindric wall, the

vcutter elements 12 being mounted in the body slots in such a manner as to be movable verti cally in the body slots and also horizontally in and out. These cutter elements 12 are shown as comprising cutter carriers 13 and provided with cutting rollers 14:; although, so far as my invention is concerned, the cutter carriers and the ultimate cutting elements may be of any form and arrangement. The cutter carriers 13 are provided with internal ribs or wings 14; at their inner vertical edges, which ribs or wings, bearing outwardly against the wall of the body, limit the outward movement of the cutters to hold them from being torn out of the body. The lower ends of the cutter carriers 13 rest upon a cutter propeller 15 which in turn rests upon a cutter actuating spring 16 whose lower end is shown as resting on a collar 17 supported by the screw-threaded pin 18 of the drill bit 19 that is attached to the lower end of the reamer body. The rotatable mandrel 20 is mounted within the tubular body. The upper cylindric part 20 of this mandrel is provided with a collar 2O which is confined bet-ween the upper end of the body proper 10 and a cap 10' screw-threaded to the upper end of the body. The upper end of the mandrel is provided with a screw-threaded pin 20 of the usual tool joint type, so that the upper end of the mandrel may be connected to the drill stem or to a sub 20 which connects with the drill stem. Thus, through the medium of the drill stem the whole tool may be raised and lowered and the mandrel may be rotated either within the body or, as hereinafter exbeing relatively shallow a-nd the other set 31 being relatively deep. Between the adjacent grooves 30 and 31 the mandrel has ribs or ridges 32, the lower ends of these ribs or ridges may be provided with overhanging downwardly facing shoulders 33 (best shown in Fig. 6) under which the correspondingly shaped ledges 13 of the cutter carriers 13 bear upwardly when the parts are in the contracted position shown in Fig. 2. Below the grooved mandrel part the mandrel has a smaller cylindric portion 35 whose diameter is about the same as the diameter through the mandrel between the bottoms of the deep grooves 31; and from the cylindric part 35 conical surfaces 36 lead upwardly and outwardly to the bottoms of the shallow grooves 30. Below the small cylindric part 35 the mandrel has a downwardly tapered part 37 which acts as an inner abutment for the lower bearing faces 38 of the cutter carriers 13 when the cutters are in their expanded positions. The water tube 39 forms a downward extension of the mandrel to extend the water passage 40 on down into the spring chamber and to the drill bit, the cutter propeller 15 and spring 16 surrounding this water tube 39.

From what has been said and from the consideration of the various figures the operation of the reamer may now be readily understood. The reamer may first be lowered into the hole, through the well pipe, in the condition shown in Figs. 2 and 4 with all of the cutters in their relatively lowered position and with the mandrel in such a rotative position that each cutter is overhung by one of the downwardly facing shoulders 33 of the mandrel. The cutters are thus held down. In fact, due to the conformation of the mandrel shoulders 33 and their engagement with the carrier latches 13*, the cutters are locked down and cannot be moved up by the spring 16 until the mandrel is rotated. WVhen the tool has reached a position where it is desired to put it to work, then relative rotation I of the mandrel inside the body, through an angle of 45, rotates the mandrel shoulders 33 away from their positions over the cutter carriers and rotates the mandrel grooves to position above the cutter carriers. The relative rotative position is then such as is shown in Fig. 3 or Fig. 5. In this position the spring can move the cutter carriers up into the mandrel grooves, and in doing so the cutter carriers which are moving up into the shallow grooves 30 are moved outwardly at their upper ends, due to the diagonal action of the conical faces 36, and thus those cutters are moved outwardly to expanded position, such as shown in Fig. 1. The other pair of cutters, however, is not moved outwardly as they are moved upwardly in the deep grooves 31 of the mandrel; because as is best shown in Figs. 7 and 9 the bottoms of the deeper grooves 31 are substantially in line with the exterior surface of the mandrel part 35 against which all of the cutters rest when the cutters are collapsed. Relative mandrel rotation to bring the mandrel grooves over the cutter carriers is preferably always righthanded. The body retardation necessary for" this slight relative mandrel rotation may be obtained from frictional contact of the body and cutters with the pipe just above its lower end or by occasional frictional contact of the body or cutters with the walls of the hole below the pipe, as the tool is rotated. It will be noted that only a slight mandrel rotation is necessary to put the parts in relative position for expansion; and the slight retarda-- tion necessary for that slight relative rotation may be obtained by such frictional or oocasional striking contact. On the other hand,

instead of utilizing locking shoulders at 335 on the mandrel, the shoulders may be relatively reversed in their diagonal extent, as shown at 33 in Fig. 10, so that there is conthe cutters due to the upward action of spring 16; and the cutters thus being atleast slightly forced out into contact with the well pipe or the walls of the hole, there is always and body so as to provide for the necessary relative rotation of the mandrel.

After the rotative movement is accom-' plished it will be seen that in one relative position of the mandrel, as for instance in Fig. 3, one set of cutters isexpanded by upward movement into the shallow mandrel slots 30. This expanded set of cutters may be Worked until they are worn or until for any other reason it is desired to use the other set. Then by pulling the tool up against the lower end of the casing or the casing shoe theexpanded cutters will be forced down forc in Fig. 4. Then the mandrel may be rotated further in a right-handed direction through an angle of 90, which will bring the shallow" slots 30 to position above the other set of cutters, and upon subsequent loweringofthetool the other set of cutters will move up into the shallow slots and be expanded as shown in Fig. 5. \Vhenever it is desired to remove thetool from the hole, merely pulling it up wardly will always force the cutters down to contracted position when the tool may be pulled out through the casing; or if it is desired to lock the cutters downto keep them from being pressed outwardly by the spring action against the inside of the casing by being Withdrawnthe mandrel may be rotated through an angle of to bring the mandrel shoulders 33 or 33 above the cutter carriers. In order to facilitate rotation of the mandrel to bring the shoulders 33 above the cutter carriers, these shoulders 33 may be arranged to be slightly diagonal (helical) in stant tendency to expand the upper ends of a cutter contact that will retard the cutters "position, as is show-n best in Figs. fi -andlo, tothat if the cutters are not pushediclear downto I theirlowermost positions by. :conta'ct with the casing, rotat-ioniof the' mandrel and the diagonal action of the shoulders #33 or: 33 will cause the cutters to be pushed down far enough a to allow 1 the mandrel shoulders to'ride over them.

I havedescribed the mandrel as having :two sets of grooves, one relatively. shallow'and; the other relatively deep; The presence of the relatively shallow grooves, however, :as grooves in the surface'of'the mandrel, .is=:only occasioned by the presence of the. 'ribsor ridges 32-between the adj acenti grooves and g the function of these ribs o-r :ridges is primarily" only to presentthe downwardly facing mandrel shoulders33 or 3 3"which-are posi- 'ti'oned above the cutter carriers when the .cut-

ter 'carriersiare intheir lowerzcontractedlposia tions. Although such ribs or ridges,. and their'downwardly facing shoulders, are desirable, they are not absolutely necessary ito the structureand'functions ofthe'tool acting' as a changeable cutter reamer. Console, quentl y, and at least. in the broader aspects of my invention, such ribs or ridges imay be ignored, .and the .bottom surfaces .or theirelatively shallow grooves thus become. merely outwardly facing surfaces-of ithe mandrel at; radii greater't'han the "bottoms of: the relatively deeper: grooves.

I claim:

1'. A changeable cuttertreamer, comprising a body, a i mandrel within and rotatable with; relation'to the body, theunandrelthavingcutt'er: abutment surfaces angu'larly spaced "from each other about the. axis of rotationmand 'lo cated at different radii from theax is' ofro- {tation, and two cutters 1 mounted: in .theibody to= movein' and out spa-cednfr'om each other angularly in correspondence with the angular separation :of thetwo :surfaces onsthe mandrel.

2. changeable cutter reamer, comprising? a-bod'y, .a mandrel within and rotatable with relation to the body, the TIIIELIIClI Ql having outwardly facing cutter abutment surfaces angularlyspaced from each other aboutthe axis of rotation andlocated at diif'erent radii': fromth'e axis of rotation, and two :cutt'ers mounted in the "body: for movement longitudinallyrelative tozthe mandrel and also'for inovementin and'out in the body, said two cutters being angu lar ly'spaced from each- 120 other in correspondence with. the angular spacing of the two surfaces on the-mandrel.

A changeable cutter reamer. comprising a tubular body having" two sets of opposite slots through its tubular wall, said'wall slotsbeing angularlyspaced equi-distantly around the axis of the body, two sets of cutters mounted in said wall slots to move in and out therethrough, a mandrel within the body and rota-table relative thereto, said mandrel hav 1 5 distance from -the mandrel center than the other.

4. A changeable cutter reamer comprising a tubular body having two sets of opposite slots through its tubular wall, said wall slots r being angularly spaced equidistantly around I y the arms of the body, two sets of cutters mounth ed in said wall slots to move in and out therethrough and to move longitudinally. therein, a mandrel within the body and ro- 5 tatable relative thereto, said mandrel having two sets of oppositely disposed outwardly facing cutter abutment surfaces, said surfaces being equi-angularly spaced about the center of the mandrel, and one set being at a greater at 2 radial distance from the mandrel center than the other.

5. A changeable cutter reamer, comprising a tubular body having two sets of opposite and longitudinally extending slots through r its wall, the several slots being equi-angularly spaced aboutthe center of the tubular body, cutters mounted in said slots to move longitudinally therein and in and out therethrough, means for moving said cutters upwardly loni gitudinally in the slots, a central mandrel mounted within the body between the several cutters and rotatable with reference to the body, said mandrel having two sets of opposite outwardly facing cutter abutment surfaces,

said several surfaces being equi-angularly spaced about the center of the mandrel and body, and one set of said surfaces being at a greater radial distance from said center than the other.

- I 40 6. A changeable cutter reamer, comprising v cutters mounted in said slots to move lona tubular body having two sets of opposite and longitudinally extending slots through its wall, the several slots being equi-angularly spaced about the center of the tubular body,

gitudinally therein and in and out therethrough, means for moving said cutters upwardly longitudinally in the slots, and a mandrel mounted within the body between the several cutters and rotatable with reference to the body and cutters, said mandrel being provided with two sets of opposite grooves in its surface, said several grooves be ing equi-angularly spaced about the center of rotation of the mandrel and one set being relatively shallow and the other set being relatively deep.

In witness that I claim the foregoing I have hereunto subscribed my name this 3d day of July 1928. I 1 1 STEWART L. CAMPBELL. v; 

